Refrigerating apparatus



May 16, 1939.

H. B. HULL ET AL REFRIGERATING APPARATUS 1931 2 Sheets-Sheet 1 Original Filed Aug. 51

INVENTORS.

BY 4WM 77/5/3 ATTORNEY H. B. HULL ET AL ,5 2

REFRIGERATING APPARATUS 2 Sheets-Sheet 2 Original Filed Aug. 31, 1931 lNVliNTO/(S.

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I BY a Tiff/2 Patented May 16, 1939 UNITED STATES PATENT OFFICE Ohio, assignors, by

mesne assignments, to

General Motors Corporation, a corporation of Delaware Application August 31, 1931, Serial No. 580,360 7 Renewed December 10, 1936 20 Claims.

This invention relates to refrigerating apparatus and more particularly to refrigerating systems having a plurality of evaporators which are to be maintained at different temperatures.

In refrigerating practice it is often desired to employ a single refrigerating system capable of producing a plurality of different refrigerating temperatures. To do this a special control valve,

usually called a two-temperature valve, has been employed to obtain a different pressure within one of the evaporators which may be employed in such a system, and thus provide evaporators of different temperatures.

The objects of my invention include provision of an improved, eflicient, refrigerating system which provides a plurality of refrigerating temperatures without the necessity of the use of such a two-temperature valve.

A more specific 'object of the invention is to provide a compressor which may operate on more than one back pressure simultaneously.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a view showing'my improved refrigerating system;

Fig. 2 is a top view of a portion of the compressor shown in Fig. 1;

Fig. 3 is a horizontal sectional view through a portion of the compressor including the gyrator; t

Fig. 4 is an enlarged view of a portion of Fig. 2;

Fig. 5 is a fragmentary vertical sectional view through the outlet ports showing the gyrator ring in one position;

Fig. 6 is a fragmentary vertical sectional view 40 through the outlet ports showing the gyrator ring in another position; and

Fig. 7 is a view partly in section of a compressor incorporating a form of the invention in which more different evaporating temperatures may be 5 obtained than with the compressor shown in Figs.

1 to 6 inclusive. v

For the purpose of illustration I have shown my invention as applied to a soda-fountain. In Fig. 1 there is shown a soda fountainZll provided 5 with an ice cream compartment comprising insulating brine tank 2! containingthe coil of an 1 evaporator 22 therein. The cylindrical cans 23 for holding ice cream or similar food articles project downwardly into the brine tank 2!. At 55 the side of the ice cream compartment is a sec- 0nd compartment 24 which contains the-refrigv erating coils of an evaporator 25 and water 0001- ing coils 26 which are provided for cooling the water dispensed at the fountain. Brine surrounds both the evaporating coil and the water cooling 5 coil and in this manner effects a transfer of heat and cold between the water coils and the refrigerating coils. It is essential that the ice cream cans be kept at a temperature below freezing to prevent melting and spoiling of the ice 10 cream while the water coils should be kept at a somewhat higher temperature so as not .to make the water dispensed for drinking purposes uncomfortably cool or to freeze the water. The temperature desired for the drinking water is 16 preferably from to F.

It will therefore be seen that it is necessary to keep the evaporators 22 and 25 at different temperatures. To do this, different evaporating pressures are employed which correspond to the desired different evaporating temperatures. The compressor 30 is employed for supplying evaporators 22 and 25 with liquid refrigerant and for maintaining the pressure within these evaporators at a diiferent figure. The compressor 30 is 25 provided with a main housing 3| which comprises the central portion of the compressor. This main housing 3| is provided with a top cover 32 which is fastened thereto by the cap screws 33 and a bottom plate 34, also fastened to the main houso ing 3| by cap screws 35. A boss 36 is provided in the bottom plate for supporting the bearing 31 within which the lower end of the driving shaft 38 is rotatably supported. This driving shaft has a rotor '39 of an electric motor mounted upon its 35 center portion. The upper end of the driving shaft 38 is mounted within the bearing 40 which is fixed within the upperportion of the housing 3|. Surrounding the rotor 39 is the stator portion ll of the electric motor which is used to drive 40 the compressor.

The compressor is preferably of the gyratory ring t and for this purpose a groove 42 is provided in the top surface of the main frame 3|. The gyrator 43 comprises a disc-shaped plate 5 having a ring depending from its lower surface which extends within the groove 42. This ring 44 on the bottom of the gyrator has a depth substantially equal tothe depth of the groove 42 but its width is materially less so that this ring may take an eccentric position within the groove as shown in Fig. 2. The disc-shaped plate portion of thegyrator it rests upon the machined top surface of the main frame 3|.

At one side of the ring 44 there is provided a notch which receives a divider element 45 which has rounded ends which fit within bearing surfaces which-are cut in the sides of the groove 42. A pair of inlet ports 46 and 41 are provided at one side of this divider element while a plurality of outlet ports 48 are provided at the other side of the divider element 45. One of the inlet ports 46 leads to the outer portion of the groove 42 ad- 1 jacent the divider element 45 while the other inlet port 41 leads to the inner side of the groove 42. The gyrator fits upon the ball bearing 5| which is mounted on an eccentric 52 at the end of the vertical shaft 38. A counterbalance 53 is provided at both sides of the gyrator 43 so as to balance the unbalanced force and weight of the gyrator 43 as well as the eccentric 52. The eccentric 52 moves the ring 44 around the groove 42 so that the outer side of the ring touches the outer side of the groove 42 at one point while the inner side of the ring touches the inner side of the groove 42 at a diametrically opposite corner. When the vertical shaft 38 is turned by the electric motor, these two points of contact revolve around the groove and force and suck the gas from the inlet ports and forces it around the groove to the outlet ports 48 provided with flapper valves I04 where the gas is discharged into a chamber 54 beneath the top cover 32. The chamber 54 and the motor chamber connect through the spaces between the balls of the bearing 5| and the ducts I03.

The compressed gas which is discharged into the chamber 54 at the top of the ,compressor is conducted by a conduit 65 to the condenser 86 where the compressed gas is condensed. This condensed gas is collected in a receiver 61 at the bottom of the condenser 66. From the condenser the condensed refrigerant is conducted by a conduit 68 and by a branch conduit 69 to an automatic expansion valve 10 of a suitable type such as shown in Patent 1,742,323 to Slagel dated January 7, 1930, which valve is situated at the inlet of the refrigerant coil 22 which supplies refrigerant for the ice cream portion of the soda fountain 20. A branch conduit 1| conducts liquid refrigerant from the conduit 68 to an expansion valve 12, of a character similar to the valve 10, but adjusted for a different evaporator pressure, situated at the inlet of the water cooling evaporator 25. The suction conduits 6| and 62 connect the evaporators 22 and 25 respectively to the unloading chambers 56 and 58 respectively. A passage .55 connects the inlet port 46 with an unloading chamber 56 at the side of the compressor. Another passage 51 connects the port 41 with an unloading chamber 58. Each of these unloading chambers have check valves 59 and 60 respectively immediately beneath them which close when no gas is drawn from the suction conduits 6| and 62. The check valves 59 and 60 are placed within the suction passages 13 and 14 beneath the unloading chambers 56 and 58 respectively.

According to the present invention an unloading passage 15 connects the passage 55 with the chamber 54 to unload the outer compressing portion of the gyrator while an unloading passage 16 connects the passage 51 with motor chamber and the chamber 54 to unload the inner portion of the gyrator compressor. A valve 11 is opened by a solenoid 18 and closed by a spring 19 to load or unload the outer portion of the gyrator compressor. A valve 80,'which is closed by a solenoid 8| and opened by a spring 82, opens and closes the passage 16 to load or unload the independently of each other.

inner portion of the gyrator compressor. These solenoids are controlled by thermostatically controlled switches. A thermostatic switch 85 connected by a conduit 86 to a thermostatic bulb 81 is immersed within the brine tank 2| adjacent the refrigerating coil 22. The current for operating the solenoids and the electric motor is supplied through the electric conduits 88 and 89. The switch 85 is connected to the electric conduit 88 and is provided with a plurality of contacts 90 and 9|. When the snap acting switch 85 is closed by excessive temperature Within the brine tank 2| the electric current is allowed to flow through the electric conduits 92 and 93 through the windings of the stator 4| to cause the electric motor to operate and electric current also flows through the conduit 94 to energize the solenoid 18 to close the unloading valve 11 to cause gaseous refrigerant to be pumped from the refrigerating coil 22 and in this manner cause refrigeration to take place within the coil 22.

A similar snap acting switch 96 is provided for controlling the system to provide the proper temperature and the proper refrigeration within the evaporator coil 25. This switch is connected by a conduit 91 to a thermostatic bulb 98 which is immersed within the brine in the brine tank 24 adjacent the evaporator and water cooler coils 25 and 26. The switch 96 is provided with a plurality of contacts 99 and I00. When the temperature within the vicinity of the thermostatic bulb 98 is higher than that desired, the switch 96 closes and allows electric current to flow through electric conduits |0I and 93 to operate the electric motor which drives the compressor and at the same time this switch also allows the electric current to flow through the conduit I02 to energize the solenoid 8| to close the unloading valve in order that the inner portion of the gyrator compressor becomes operative to pump gaseous refrigerant from the evaporator 25.

The switches and 96 operate wholly independently of each other and the inner and outer portions of the compressor also operate entirely When either or both of the compartments to be cooled require refrigeration, the electric motor driving the gyrator compressor is started and one or both of the unloading valves is closed as the occasion demands. The expansion valves 10 and 12 are so adjusted to allow the proper amount of liquid refrigerant to pass therethrough according to the pressures in their respective evaporators. The thermostatic bulbs' 81 and 98 so control the operation of the electric motor and the unloading valves 11 and 80 so that the proper pressure is maintained in the evaporators 22 and 25 to provide the proper refrigerating temperature in these evaporators. If only one of the evaporators requires refrigeration, one of the unloading valves will be closed and the other will open. The portion of the compressor having its unloading valve closed will operate in a normal manner and withdraw refrigerant from its evaporator as its check valve through its unloading chamber and compress this gas into the chamber 54. The other portion of the compressor will have its check valve closed and all parts of this portion of the compressor will be at a discharge pressure which is found within the chamber 54 and within the motor chamber I05. Thus when the unloading valve is open the refrigerant gas within the cham ber 54 is allowed to flow through the "unloading valve into the intake side of one portion of the compressor. If both unloading valves are open the gas from the chamber 54 is allowed to pass to both portions of the compressor and also to fill the unloading chambers 58 and 58. Thus when the motor starts the compressor is unloaded and remains unloaded until the pressure within the unloading chambers is reduced. If more than two different evaporating temperatures are desired, the gyrator member may be provided with a plurality of rings similar to the ring 44 but of a different diameter as shown in Fig. 7.

In Fig. 7 is shown a sealed unit compressor of a construction similar to that of the compressor 30 but whichis provided with a gyrator I I having two depending rings III and H2 which fit within the circular grooves H3 and H4 which have a depth equal to the depth of the rings III and H2. A notch (not shown) is provided at one side of each of the rings III and I I2 adjacent each other and a divider element (not shown) similar to the divider element 45 is provided in each of the notches. On one side of each of the divider elements are the outlet ports and valves which discharge into the chamber H5 beneath the top cover H8 of the compressor.

The inlet passage I I1 leads to the outer portion of the groove H3 on the intake. side of the divider element and the inlet passage H8 leads to the inner portion of the groove I I3. The inlet passage H9 leads to the outer portion of the groove I I4 on the intake side of the divider element for that groove while the inlet passage I20 leads to the inner portion of the groove H4. In this way four separate pumping chambers are formed, one between the outer portion of the groove H3 and the ring III, a second between the ring III and the inner portion of the groove H3, a third between the outer portion of the groove H4 and the ring' H2, and a fourth pumping chamber between the ring II2-and the inner portion of the groove I I 4. Each of the inlet passages lead to an unloading chamber (not shown) provided with a check valve (not shown) which connect to the suction conduits I2l, I22, I23 and I24 which connect to individual evaporators (not shown) which are to be kept at different temperatures.

Each of the inlet passages are provided with an unloading passage which is provided with a valve controlled by a solenoid in a manner similar to that of the compressor 30. The inlet passage H1 is provided with a solenoid controlled unloading means I25, while the inlet passage H8 is provided with a solenoid controlled unloading means, I26. The inlet passage H9 is provided with a solenoid controlled unloading means I21 while the inlet passage I20 is provided with a solenoid controlled unloading means I28. A control system similar to that shown in Fig. l is preferably employed. In this way four evaporators may be operated at four different temperatures and pressures without the use of two temperature valves. By increasing the number of gyrating rings any reasonable number of different evaporating pressures and temperatures may be obtained.

Two temperature valves may also be used in connection with either the single or multiple ring type of gyrator compressor in order to obtain additional temperatures and compressors.

While the form of embodiment of the invention I adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Refrigerating apparatus including a compressor having a plurality of pumping chambers for compressing arefrigerant, condensing means connected to the plurality of pumping chambers of the compressor for condensing the refrigerant, a plurality of evaporators connected to said condensing means for evaporating the condensed refrigerant, means for controlling the flow of the refrigerant from said condensing means to the evaporators, at least some of said evaporators being connected to different pumping chambers for withdrawing refrigerant from said evaporators, and control means responsive individually to the temperature of a plurality of said evaporators for controlling the withdrawal of refrigerant from said evaporators to maintain at least some of said evaporators connected to different pumping chambers at different temperatures.

2. Refrigerating apparatus including compressing means having a plurality of pumping chambers for compressing a refrigerant, condensing means connected to the plurality of pumping chambers of the compressing means for condensing the refrigerant, a plurality of evaporators connected to said condensing means for evaporating the condensed refrigerant, means for controlling the flow of the refrigerant from said condensing means to the evaporators, at least some of said evaporators being connected to different pumping chambers for withdrawing refrigerant from said evaporators, means for unloading said pumping chambers, and means for controlling said unloading means to maintain at least some of said evaporators at different temperatures.

3. Refrigerating apparatus including compressing means having a plurality of pumping chambers for compressing a refrigerant, condensing means connected to the plurality of pumping chambers of the compressing means for condensing the refrigerant, a plurality of evaporators connected to said condensing means for evaporating the condensed refrigerant, means for controlling the fiow of refrigerant from said condensing means to the evaporators, at least some of said evaporators being connected to different pumping chambers for withdrawing refrigerant from said evaporators, means for unloading said pumping chambers, and means responsive to temperatures adjacent said evaporators for controlling said unloading means.

4. Refrigerating apparatus including compressing means having a plurality of pumping chambers for compressing a refrigerant, a common condensing means connected to the plurality of pumping chambers of the compressing means for condensing the refrigerant, a plurality of evaporators connected to said condensing means for evaporating the condensed refrigerant, means for controlling the flow of the refrigerant from said condensing means to the evaporators, at least some of said evaporators being connected to different pumping chambers for withdrawing refrlgerant from said evaporators, an electric motor for driving the compressing means, an electric circuit for supplying an electric current to said motor, and means responsive to temperatures adjacent said evaporators for closing said electric circuit and for controlling the refrigerant pressures within said evaporators to maintain some of said evaporators at different temperatures.

5. Refrigerating apparatus including compressing means having a plurality of pumping chambers for compressing a refrigerant, a common condensing means connected to. the plurality of pumping chambers of the compressing means for condensing the refrigerant, a plurality of evaporators connected to said condensing means for evaporating the condensed refrigerant, means for controlling the flow of the refrigerant from said condensing means to the evaporators, at least some of said evaporators being connected to different pumping chambers for withdrawing refrigerant from said evaporators, an electric motor for driving the compressing means, an electric circuit for supplying an electric current to said motor, and pressure controlled means responsive to temperatures adjacent said evaporators for closing said electric circuit and for controlling the refrigerant pressures within said evaporators to maintain some of said evaporators at different temperatures.

6. Refrigerating apparatus including compress- .ing means having a plurality of pumping chambers for compressing a refrigerant, a common condensing means connected to the plurality of pumping chambers of the compressing means for condensing the refrigerant, a plurality of evaporators connected to said condensing means for evaporating the condensed refrigerant, means for controlling the flow of the refrigerant from said condensing means to the evaporators, at least some of said evaporators being connected to different pumping chambers for withdrawing refrigerant from said evaporators, unloading passages for said pumping chambers, and selective means for closing said unloading passages to control the refrigerant pressures of some of said evaporators independently of other evaporators.

7. Refrigerating apparatus including compressing means having a plurality of pumping chambers for compressing a refrigerant, a common condensing means connected to the plurality of pumping chambers of the compressing means for condensing the refrigerant, a plurality of evaporators connected to said condensing means for evaporating the condensed refrigerant, means for controlling the flow of the refrigerant from said condensing means to the evaporators, at least some of said evaporators being connected to difpendently controlling the withdrawal of refrigerant from some of said evaporators to provide different refrigerant pressures in some of said evaporators.

8. Refrigerating apparatus including a plurality of compartmentsto be cooled, a compressor having a plurality of pumping chambers for compressing a refrigerant, a condensing means for condensing the refrigerant, an evaporator within each of said compartments to be cooled for evaporating the refrigerant, means for controlling the supply of refrigerant to said evaporators, at least some of said evaporators being connected to different pumping chambers, individual means for each pumping chamber for rendering said chambers-inoperative for pumping purposes, and means controlled by the temperatures within said compartments for rendering operative said pumping chambers.

9. Refrigerating apparatus including compressing means having a plurality of pumping chambers for compressing a refrigerant; condensing means connected to the plurality of pumping chambers of the compressing means for condensing the refrigerant, a plurality of evaporators connected to said condensing means for evaporating the condensed refrigerant, means for controlling the flow of the refrigerant from said condensing means to the evaporators, at least some of said evaporators being connected to different pumping chambers for withdrawing refrigerant from said evaporators, and temperature controlled means for controlling the withdrawal of refrigerant by one of the pumping chambers independently of the other.

, 10. Refrigerating apparatus including a plurality of compartments to be cooled, a plurality of evaporators in heat exchange relation with said compartments to be kept cool, a compressing and condensing means for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporators, an electric motor for driving said compressing means, a plurality of switch means responsive individually to temperature conditions within said compartments to be cooled, said switch means being connected in parallel electric circuit relation with each other and in series with the electric motor for controlling the operation thereof, and Valve means individually controlled by said switch means for individually controlling the withdrawal of refrigerant from a plurality of evaporators by said compressing press.

11. Refrigerating apparatus including compressing means having a plurality of pumping chambers, a common driving means for said compressing means, condensing means for said plurality of pumping chambers of said compressing means, a plurality of chambers containing a medium to be kept cool, an evaporating means within each of said chambers, each of said evaporating means having its inlet connected to the condensing-means and its outlet connected to one of the pumping chambers, a plurality of switch means responsive individually to conditions of said evaporating means, said switch means being connected in parallel electric circuit relation with each other and in series with the common driving means for controlling the operation thereof.

12. Refrigerating apparatus including com pressing means having a plurality of pumping chambers, a common driving means for said compressing means, condensing means for said plurality of pumping chambers of said compressing means, a plurality of chambers containing a medium to be kept cool, an evaporating means within each of said chambers, each of said evaporating means having its inlet connected to the condensing meansv and its outlet connected to one of the pumping chambers, and automatic means for individually starting and stopping the pumping effectivness of said pumping chambers.

13. Refrigerating apparatus including compressing means having a plurality of pumping chambers, a common driving means for said compressing means, condensing means for said plurality of pumping chambers of said compressing means, a plurality of chambers containing a medium to be kept cool, an evaporating means within each of said chambers, each ofsaid evaporating means having its inlet connected to the condensing means and its outlet connected to one of the pumping chambers, and a plurality of pressure operated switch means responsive individually to conditions of said evaporating means for-individually starting and stopping the withdrawing of refrigerant by the pumping chambers.

14. Refrigerating apparatus including a plurality of compartments tobe cooled, compressing and condensing means, a plurality of evaporating means having their inlets connected to the condensing means and their outlets connected to the compressing means, each of said compartments being provided with one of the evaporating means, electrically operated means for individually controlling the Withdrawal of refrigerant through one of said outlets, an electric driving means for said compressing means, a switch means responsive to temperature conditions within one of said compartments, said switch means having a plurality of contacts, one of said contacts being electrically connected to said electrically operated means and another of said contacts being connected to the electric driving means, said switch means having another contact means electrically connected to a source 'of electrical energy for making contact with said contacts.

15. Refrigerating apparatus including compressing means having a plurality of suction inlets capable of operating at different suction pressures, a common driving means for said compressing means, condensing means connected to the outlet of said compressing means, a plurality of evaporating means having their inlets connected to the condensing means and their outlets connected to said plurality of suction inlets, and

. lets capable of operating at different suction pressures, a common driving means for said compressing means, condensing means connected to the outlet of said compressing means, a plurality of evaporating means having their inlets connected to the condensing means and their outlets connected to said plurality of suction inlets, and independent means affected independently by the temperature of a plurality of the evaporating means for starting the driving means when refrigeration is required by any one of the evaporating means and stopping the driving means when no refrigeration is required by any of the evaporating means, said independent means being also effective for independently controlling the flow of refrigerant through any one of said suction inlets.

17. Refrigerating apparatus including a compressor having a plurality of pumping chambers, a common driving means for said compressor, condensing means connected to the compressor for condensing the compressed refrigerant, evaporating means connected to the condensing means and the compressor for evaporating the refrig-' erant, and means for rendering one of said pumping chambers inoperative for pumping purposes independently of another of said pumping chamhers.

18. Refrigerating apparatus including a compressor having a plurality of pumping chambers, a common driving means for said compressor, condensing means connected to the compressor for condensing the compressed refrigerant, evaporating means connected to the condensing means and the compressor for evaporating the refrigerant, and means for rendering inoperative for pumping purposes any of said pumping chambers independently of other of said chambers.

19. Refrigerating apparatus including a compressor having a plurality of pumping chambers, a common driving means for said compressor, condensing means connected to the compressor for condensing the compressed refrigerant, evaporating means connected to the condensing means and the compressor for evaporating the refrigerant, and means for unloading one of said chambers independently of another of said chambers.

20. Refrigerating apparatus including a compressor having a plurality of pumping chambers, a common driving means for said compressor, condensing means connected to the compressor for condensing the compressed refrigerant, evaporating means connected to the condensing means and .the compressor for evaporating the refrigerant, and means for unloading said pumping chambers, and means for controlling the loading of one of said pumping chambers independently of another.

HARRY B. HULL.

ALEX A. MCCORMACK. 

